in which \(|g(\phi )\rangle =\exp (\frac{i\phi }{N}\sum _xx\hat{n}_x)|g\rangle \) . Since \(\gamma _g\)  in fact came from the
continued deformation of the boundary condition of systems
[1]} and then slightly related to the symmetry of the
Hamiltonian, this construction of the geometric phase is more
popular than the previous method. An important character is that
\(\gamma _g\)  is related to the correlation functions for the ground
state, and numerical evaluation could be implemented efficiently
[2]}, [1]}, [4]}.
